Evidence from Nondenaturing Filter Elution That Induction of Double-Strand Breaks in the DNA of Chinese Hamster V79 Cells by γ Radiation Is Proportional to the Square of Dose

Publisher Website
Google Scholar
Abstract
We have used nondenaturing filter elution performed at both pH 7.2 and pH 9.6 to measure the induction of double-strand breaks (DSBs) of Chinese hamster V79 cells by 60Co .gamma.-radiation doses between 10 and 120 Gy. The absolute DSB yields as measured by this assay were determined by using our recent calibration of the assay based upon disintegrations of 125I incorporated into the DNA. Analysis of the dose-response relationship for the induction of DSBs by 60Co .gamma. rays showed that the number of DSBs induced per dalton of DNA was proportional to the square of the applied dose throughout the dose range used. The contribution made by the dose to the first power was small at pH 9.6 and negligible at pH 7.2. These results suggest that DSB induction in cells by .gamma. rays may be entirely a two-hit event.

This publication has 23 references indexed in Scilit: